This invention relates to valve means, and more particularly to a valve which includes first and second valving spools for providing a bypass of fluid pressure therethrough.
In general, it is well-known to provide a steering valve for applying fluid pressure from a pump to a steering booster valve to in turn actuate a steering clutch yoke. Such a steering valve of this type is designed so that the pump continues to be loaded even though such pressure is not needed to actuate the steering system of the vehicle. It would by highly desirable to provide means which allow unloading of the pump when fluid pressure need not be supplied thereby to the steering system, in order to lower the load on the engine of the vehicle.
U.S. Pat. No. 3,605,809 to Thorson discloses a hydraulic valve wherein a valving spool is movable in a bore to one position wherein a pump provides fluid pressure to a motor, and to another position wherein the pump is unloaded. However, it will be noted that the structure necessary for achieving such results is relatively complex, involving a single spool defining a plurality of lands and grooves thereon.